PvP128. Interaction of corona discharge species with teflon-FEP (fluoroethylenepropylene) foils

Negatively corona discharge is a practical method of introducing electrical charges in dielectrics to produce electrets. Results have shown that the Teflon-FEP (fluoroethylenepropylene) electret charge stability is dependent on the corona atmospheres. We have carried out charging experiments on atmosphere of CO2, O2, N2, dry air and humid air. The charge stability has been studied by surface charge and thermally stimulated discharge (TSD) measurements. The corona process produces electrons, ions and neutral species. The charged species transfer their electrical charge to polymer surface traps. The activated neutral species interact with the polymer surface creating new traps or modifying the preexisting ones, being responsible for the decrease of the electret charge stability. This effect is strongly dependent on the corona atmosphere and charging time.